The present invention relates to an arrangement in a coil winding machine for winding a strandlike product, such as a cable, on a reel provided with flanges, which coil winding machine comprises
a support stand for supporting a reel rotatably around the axis thereof,
a guide for supplying the strandlike product to be wound to the reel in order to form superimposed layers of product turns wound adjacent to each other between the flanges of the reel,
a distribution machinery for displacing the support stand and the guide in relation to each other by a pitch corresponding to the thickness of the product per product turn,
detectors for detecting the reel flanges and for acting on the distribution machinery so that displacement direction between the reel and the guide is reversed, as a coil product turn contacts a reel flange, and measuring means for continuously detecting the thickness of the coil product which measuring means are connected to control the distribution machinery so that the pitch of the product turns on the reel is varied in accordance with the thickness measurement of the measuring means.
The expression "strandlike product" is in this connection intended to include all kinds of narrow endless objects, such as cables, wires, hoses and the like, which can be wound on a reel, mainly products found in the manufacture of electric cables and information transmission wires. In the following the invention will, however, for the sake of simplicity, be described in connection with a cable.
When a cable is wound on a reel or a drum, a guiding means is used to guide the cable to be situated between the flanges of the reel in layers positioned on top of each other, each layer consisting of a number of adjacent cable turns.
In most known coil winding machines, eg U.S. Pat. Nos. 4,143,834 (FURUKAWA), 4,150,801 (KOBE STEEL) and 3,997,128 (FURUKAWA), the winding movements are carried out by an axial displacement of a cable guide and the reel in relation to each other in the axial direction of the reel so that when the reel has rotated one turn, the guide or the reel has moved over a distance corresponding to the thickness of the cable. Known coil winding machines are normally adjustable for handling of reels having different drum diameters and different distances between the flanges. The machines are also provided with a distribution machinery, by which the axial displacement between the guide and the reel per each coil turn, ie the pitch by which the cable is wound on the reel, can be adjusted in each case to correspond with the thickness of the cable to be wound.
A considerable drawback of these known coil winding machines is that the machine operator, when initiating the winding, has to manually adjust the distribution machinery so that the pitch of the cable corresponds to the cable thickness in question. After this the cable is wound by the guide on the reel by a constant pitch from flange to flange. If the thickness of the cable, eg due to an incorrect measurement, does not exactly correspond to the adjusted pitch, or if the cable thickness varies over certain cable lengths from the measured value so that undesired spaces are formed between the cable turns, this may substantially disturb the winding process and impair the winding result.
A further disadvantage is that the machine operator, when initiating the winding, has to manually adjust the turning points for the reversal of the distribution machinery at the reel flanges so that the turning positions correspond to the width or flange thickness of the reel in question. The adjusting of the turning points is usually effected by the operator by moving mechanical limit switches or similar detectors of another type. Besides this being time-consuming, the adjusting often turns out wrong even if the displacement is carried out to a corresponding marking on a graded scale. This is due to the fact that the width and the flange thickness of the reels are not always constant among reels of the same size and type. In particular wooden reels have a tendency to open up and increase in width to a different degree, because the axial tension bars of the reel have yielded. The machine operator must therefore watch every turning point when the cable reaches the inside of the reel flange, and furthermore often intervene so that the turning point does not get too misplaced and result in spoiling of the winding process. It is namely important for the achievement of a closely and optimally filled reel that a good filling is achieved at the flange during the winding of the cable, in order to prevent subsequent cable layers from falling down into possible spaces between the cable and the reel flange in an underlying cable layer.
The U.S. Pat. No. 4244539 refers to a more advanced coil winding machine, in which a measurement of the thickness variations of the cable is utilized in order to control the winding process of the cable ie the operation of the distribution machinery. The displacement of the guide and accordingly the pitch of the cable on the drum are hereby adjusted in accordance with the thickness measurement. For this purpose the internal width of the reel and the diameter of the cable are measured, where-after the amount of wound turns between the reel flanges is calculated, and the displacement of the guide is calculated by means of appropriate computer equipment. Also the reversal of the guide at the reel flanges is affected by the thickness measurement by calculating the amount of wound turns based on the thickness variations.
Also a coil winding machine according to this embodiment has a substantial disadvantage, namely that all these necessary computer calculations and adjusting measures caused thereby are time-consuming and result in that the reversals at the reel flanges take place too late resp. too early, particularly at high line rates, if the calculations are lagging behind.
An object of the present invention is to provide an arrangement in a coil winding machine, which avoids the above mentioned disadvantages and enables adjusting of the positions of the turning points in order to automatically take into account the variations of the cable thickness. This is achieved by an arrangement according to the invention, which is characterized in
that the detectors for detecting the reel flanges are arranged to be mechanically displaced each by a measuring means over a distance corresponding to the displacement of the measuring means from a determined thickness position due to deviations in the coil product thickness.
The invention is based on the idea of mechanically connecting a continuous detection of the thickness of a strandlike product, a cable, with an adjusting of the positions of the detectors, which detect the reel flanges and directly affects the reversal of the distribution machinery. In this way the detectors will be directly, without demanding calculations, adjusted by the measuring means and accordingly the positions of the turning points of the reversal will be automatically and instantly changed in accordance with the thickness variations of the cable. This results in the achievement of a tight and optimal winding of the coil even at the reel flanges quite automatically without the need of manual supervision of and intervention in the winding process.